Hemming attachment for sewing machines



April 14,1942.- P, ENOS' 2,279,588

' HEMMING ATTACHMENT FOR SEWING MACHINES Filed March 6, 1940 2 Sheets-Sheet l mi Ill 1 1 um nmmnmIi 7 3am John 1? 6258' Wilma:

April 14, 1942. .1. P. ENOS HEMMING ATTACHMENT FOR SEWING MACHINES Filed March 6, 1940 2 Sheets-Sheet 2 Patented Apr. 14, 1942 HEMMING ATTAOHll/[ENT For; SEWING MACHINES John P. Enos, Elizabeth, N. .I., assignor to The Singer Manufacturing Company,

Elizabeth,

N. J a corporation of New Jersey Application March 6, 1940, Serial No. 322,434

15 Claims. (01. 112-141) This invention relates to hemming attachments for sewing machines and particularly to a narrow hemming attachment for edge-folding the margin of a cravat or handkerchief and directing the same so folded to the stitching mechanism of a sewing machine.

A primary object of the invention is to provide a hemming attachment of the spiral type having provision whereby its capacity can be varied automatically in response to the passage therethrough of unequal thicknesses of material.

Another object of the present invention is the provision of a yieldable spiral section which functions to maintain the material being hemmed in engagement with the spiral foldingedge of the attachment, whereby the tendency of the material to shift laterally out of the attachment during the hemming operation is reduced to a minimum.

A further object of the invention is to provide a hemming attachment whereof one of the spiral scrolls, which frequently breaks during usage because of frailty resulting from its required special heat-treatment, can be replaced conveniently and quickly, thereby increasing materially the life of the attachment.

A still further object of the invention is the provision of a hemming attachment having the above noted features, the elements of which are simple in construction, inexpensive to manufacture, and susceptible of convenient assembly and replacement.

With the above and other objects in View, as

will hereinafter appear, the invention comprises the devices, combinations, and arrangements of parts hereinafter set forth and illustrated in the accompanying drawings of a preferred embodiment of the invention, from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

In the accompanying drawings:

Fig. 1 is a side elevation of a scroll-hemmer embodying the present invention. 1

Fig. 2 is a top plan View of the scroll-hemmer, partly in section, showing the pivotal mounting for the yieldable scroll-section.

Fig. 3 is a vertical section taken substantially along the line 3-3, Fig. 1. g

Fig. 4 is a vertical section taken along the line 44, Fig. 1. p

Fig. 5 is a vertical section taken along the line 5-5, Fig. 1. I

Fig. 6 is a perspective View of the casing inverted to show its construction.

. tion 9.

Fig. 11 is a vertical sectional view taken sub- .stantially along the line "-1 I, Fig. 8.

Fig. 12 is a side elevation, partly in" section, of a second modification, showing a scroll-hemmer whereof the secondary scroll-section is adapted to be initially adjusted and maintained in such position by a set-screw.

Referring more in detail to the drawings, the hemming attachment illustrated in Figs. 1 to 7, inclusive, comp-rises a base-plate I fitted at one end with a depending securing-screw 2 adapted to project through a suitable aperture 3 provided in the usual cloth-plate 4 of a conventional sewing machine and have threaded thereon a clampnut 5. Integral with the other end of the baseplate i is a depending end-portion 6 entering a recess 1 in the cloth-plate 4 to more securely retain the hammer in proper alinement relative to the stitching mechanism. On the upper surface of the base-plate l is soldered, or otherwise fastened thereto, a substantially O shaped bracket 8, the upper horizontal limb of which supports a primary spirally formed scroll-sec- The primary scroll-section is made of relatively heavy stock and is not adapted to yield appreciably in response to inequalities in the thickness of materials being, hemmed.

Cooperating with the primary scroll-section 9 is a relatively thin secondary scroll-section I0 twisted with the primary scroll-section to provide between them a spiral passageway extending toward the needle and within which the marginal edge of the fabric is adapted to be placed. The secondary scroll-section l0 ispreferably composed of spring steel and is heat treated to render it inherently yieldable to a limited extent. In scroll-hemmers-of the type in question as previously constructed, an example ;of

which is shown in the us. patentto .c. H. W111- cox, No. 43,657, dated July 26,1864, the secondary scroll-section was formed with an integral shank permanently secured'upon the base-plate. In this construction, the capacity of the hemmer was limited by the degree of inherent flexibility of the secondary scroll-section. If the capacity of the hemmer was exceeded, excessive resistance to the passage of fabric through the hemmer was experienced, which resulted either in an imperfectly formed hem or a choked hemmer. In addition, since the secondary scroll-section was rigidly secured to the base-plate the capacity of the spiral fabric-receiving passageway H adjacent the mouth of the hemmer was definitely established, and if a material of less thickness than the depth of the spiral passageway was used, it was essential that the fabric be presented to the hemmer in such a way as to completely fill widthwise the fabric-receiving passageway II at the mouth of the hemmer. This was necessary because the spiral fabric-turning edge 12 of the secondary scroll-section l0, being spaced a predetermined distance from the primary scroll-section 9, did not pinch the fabric against the primary scroll-section and cause it to definitely follow the spiral fabric-turning edge l2.

The present invention resides intthe provision of an adjustable or yie'ldable secondary scrollsection whereby the fabric-turning edge thereof is maintained yieldingly in contact with the primary scroll-section to effectively control the fabric-margin being folded, and whereby the capacity of the hemmer maybe varied in response to the thickness of the material being hemmed To this end the secondary scroll-section Ill is attached at one end to a cylindrical shank I3 journaled for limited oscillation in the open-ended bearing apertures l4 formed in the up-turned' end-portions l5 and IE or a bearing- 7 member H. The bearing-member I7 is preferably fastened upon the base-plate l by a screw 18. Formed on the upturned end-portion 16 of the bearing-member H are two horizontal lugs [9 which, as shown in Fig. l, are adapted to be received in the horizontal limbs of the bayonetslots 20 provided in the side-walls of a hollow semi-cylindrical casing 2 The casing 2i is tapered at its forward end, as at 22, to facilitate the passage thereover of the fabric being hemmed. Extending forwardly from the base of the tapered end 22 of the casing 2i is .a finger 23' which projects-beneath a suitable bracket 24 riveted or otherwise secured to the base-plate I.

The finger 23 and the screw 18 detachably secure the casingand the parts housed and supported thereby upon the base-plate I.

As observed in Figs. 1 and2, the cylindrical arbor l3 adjacent the upturned end-portion I6 of the bearing member i1 is oiIset, as at 25, to prevent endwisemovenient of the arborin the direction of the normal feedof the fabric through the attachmenh and extended, as at 25, to provide a support for acoil-s'pring 21. The coilspring has one of its ends secured to the extended portion 26' of the arbor and its other end 2 8 bearing against the casing 2|. The function of the coil-spring 21 is to yieldingly bias the secondary scroll-section in aclockwise direction (when the hemmer is viewed in the direction of travel of the fabric) about-the longitudinal axis of the arbor l3 to cause the spiral fabric-turning edge 12 of the secondary scroll-section to pinch the fabric against the primary scroll-section and thereby forcibly cause it to follow the fabric-turning edge I 2. addition, the pinching of the fabric between the primary and secondaryscroll-secti'on's prevents the fabric from working itself out of the hemmer during its passage therethrough;

In the event the secondary scroll-section is broken or otherwise damaged, it can be conveniently replaced by first removing the screw I8, then sliding the casing 21 and the elements carried thereby rearwardly to release the finger 23 from the bracket 24. The casing 2| may then be inverted to expose the bearing-member I! which can be shifted relative to the casingto release the lugs [9 from the bayonet-slots 20, When the bearing-member II is released from the casing 2| the arbor l3 carrying the secondary scroll-section l0 drops out of the openended bearing-apertures l4, permitting the coilspring 2'! to be conveniently removed from the arbor. The damaged scroll-section can then be discarded and a new one substituted therefor. The hemmer may be assembled by following the above described steps in reverse order.

The hemmer shown in Figs. 8 to 11, inclusive, is a modification of the device illustrated in Figs. 1 to 7, inclusive. In the modification, the secondary scroll-section H] is formed with a substantially U-shaped shank 23, the horizontal portion of which is adjustably or slidably held in contact with the upper surface of the base-plate I by an overlying retaining strip 33 secured at one end to the base-plate. As shown in Fig. 11, the retaining-strip 3B is spaced from the upper surface of the base-plate to permit the shank 29 of the secondary scroll-section to shift laterally in response to inequalities in the thickness of the fabric being hemmed. The retainingstrip 30 is bent at 3-! to provide a stop against which the side of the shank 29 of the secondary scroll-section is yieldingly maintained by a spring 32 coiled about-an upstanding lug 33 preferably formed as a continuation of the securing-screw 2. The spring 32 is formed with two arms 34 and 35, the arm 34 being bent at its free end and hooked through an aperture 36 provided in the vertical limb 3? of the shank of the secondary scroll-section. The arm is also bent at its free end and is disposed beneath a tongue 38 struck-up from the base-plate l. Housing the spring 32 and the U-shaped shank 29 of the secondary scroll-section I0 is the casing 2! which is secured in place by a screw 39 threaded into the lug 33.

In the modification illustrated in Figs. 8 to 11, inclusive, the secondary scroll-section is adapted to yield transversely of the line of feed in response to inequalities, such as cross-seams, in the thickness of the fabric being hemmed. In Fig. 9 the shank 29 of the secondary scroll-section is in contact with the stop 3|, while in Fig. 10 the shank 29*is shown shifted away from the st'op3'l crosswise of the seam-line. This adjusting or shifting of'the secondary scroll-section permits an automatic change in the capacity of the scroll hemmer, thereby adapting the device to accommodate a variety of different materials and also to eliminate possible overloading of the hemmer resulting- -from traversing cross-seams and the like in the fabric. It will be understood that the secondary scroll-section can be readily replaced by removing the casing 2! and unhooking the arm .34" .of the spring 32 from the shank of the secondary scroll-section.

Referring now to Fig. 12, the hemmerdisclosed is a second modification. It will be observed that in this device the secondary scroll-section IO'is soldered, or otherwisesecured, to a cylindrical shank 40 adapted to be adjustably received in an aperture 4lprovided in the casing 2|.

Threaded into the bottom of the casing 2| is an adjusting set-screw 42 which bears against the shank 40 and locks the secondary scroll-section in the desired position. The head of the screw 42 projects through a clearance aperture 43 in'the base-plate I. The casing 2| is fastened to the base-plate bytwo screws 44 and 45. In this modification the capacity of the scrollhemmer is not automatically varied to accommodate inequalities in the thickness of the fabric, but may be initially set to the desired amount by removing the hemmer from the cloth-plate of the sewing machine to expose the adjusting setscrew 42, which can be unscrewed to release the shank 48 of the secondary scroll-section. The secondary scroll-section can then be turned about the axis of the shank 40 to the desired position and then looked in such position by the set-screw 412. It will be seen that in the case of injury to the secondary scroll-section it can be readily replaced by releasing the set-screw 42 and substituting a new scroll-section for the damaged scroll-section.

In each of the modifications illustrated, it will be seen that the base-plate I in advance of the receiving end. of the hemmer has mounted thereon the casing 2|. The casing in its preferred form is semi-cylindrical and functions to encompass the shank of the secondary scroll-section ll! of each of the modifications, and also to provide a smooth fabric-supporting platform for facilitating the proper presentation of the fabric to the fabric-receiving passageway I I defined by the spiraled scroll-sections.

Having thus set forth the nature of the inven tion, what I claim herein is:

l. A hemming attachment for sewing machines comprising in combination, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section cooperating with said primary scroll-section to define between them a fabric-receiving passageway, a shank to which said secondary scroll-section is fixed, and means for supporting said shank for circular adjustment about the longitudinal axis of said shank.

2. A hemming attachment for sewing machines comprising in combination, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section twisted with said primary scroll-section to define a fabric-receiving passageway, a shank to which said secondary scroll-section is secured, and means including a spring for supporting said shank for yieldable turning movement about the longitudinal axis of said shank to vary the capacity of the fabricreceiving passageway.

3. A hemming attachment for sewing machines comprising in combination, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section having a fabricturning edge and twisted with said primary scroll-section to define a fabric-receiving passageway, a shank to which said secondary scrollsection is secured, a bearing member provided with a bearing aperture in' which said shank is journaled, and a spring adapted to bias the fabric-turning edge of said secondary scroll-section toward said primary scroll-section to forcibly cause the fabric to follow said fabric-turning edge.

4. A hemming attachment for sewing machines comprising in combination, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section having a fabricturning edge and twisted with said primary scroll-section to define a fabric-receiving passageway, a shank to which said secondary scrollsection is secured, a bearing member secured to said base-plate and formed with an open-ended bearing aperture in which said shank is journaled, a spring adapted to bias the fabric-turning edge of said secondary scroll-section toward said primary scroll-section to forcibly cause the fabric to follow said fabric-turning edge, and a casing adapted to house said spring and close the open end of said bearing aperture to prevent the dislodgment of the shank of said secondary scroll-section.

5. A hemming attachment for sewing machines comprising in combination, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section having a fabricturning edge and twisted with said primary scroll-section to define a fabric-receiving pas sageway, a shank to which said secondary scrollsection is secured, a bearing member formed with a plurality of lugs and with a bearing aperture in which said shank is journaled, a spring adapted to bias the fabric-turning edge of said secondary scroll-section toward said primary scroll-section to forcibly cause the fabric to follow said fabric-turning edge, and a casing adapted to house said spring and said bearing member, said casing being provided with a plurality of bayonet-slots adapted to receive the lugs of said bearing member thereby to secure the casing in position upon the base-plate.

6. A hemming attachment for sewing machines comprising, a base-plate having a bracket, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section having a fabricturning edge and twisted with said primary scroll-section to define a fabric-receiving passageway, a shank to which said secondary scrollsection is secured, a bearing member attached to said base-plate and aperturedto receive the shank of said secondary scroll-section, a, spring adapted to .bias the fabric-turning edge of said secondary scroll-section toward said primary scroll-section to forcibly cause the fabric to follow said fabric-turning edge, a casing adapted to house said spring and facilitate the passage of the fabric thereover, said casing being formed with a finger adapted to project beneath the bracket on said base-plate, and means for detachably securing the casing to said bearingmember.

7. A hemming attachment for sewing machines comprising,a base-plate, a longitudinally spiraled primary scrollesection secured to said base-plate, a longitudinally spiraled secondary scroll-section twisted with "said primary scrollsection to define a fabric-receiving passageway, a shank fastened to said secondary scroll-section and connected to said base-plate for lateral slidable movement relative to said primary scroll-section, and a spring for biasing said secondary scroll-section toward said primary scrollsection.

8. A hemming attachment for sewing machines comprising, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section twisted with said primary scrollsection to define a fabric-receiving passageway, a shank integral with said secondary scroll-section and having a horizontal portion in contact with said base-plate, a retaining strip secured to said base-plate and overlying said horizontal portion for slidably maintaining said shank on said base-plate, and a spring engaging said shank for biasing said secondary scroll-section toward said primary scroll-section.

9. A hemming attachment for sewing machines comprising, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section twisted with said primary scrollsection to define a fabric-receiving passageway, a shank integral with said secondary scroll-section and connected to said base-plate for limited transverse movement, a spring adapted to bias said secondary scroll-section toward said primary scroll-section, and a detachable hollow casing adapted to house said shank and spring to facilitate the passage of fabric thereover.

10. A hemming attachment for sewing machines comprising, a base-plate having an upstanding lug, a spiraled primary scroll-section secured to said base-plate, a spiraled secondary scroll-section twisted with said primary scrollsection to define a fabric-receiving passageway, a shank integral with said secondary scroll-section and having a horizontal portion in contact with said base-plate, means for slidably maintaining said shank upon said base-plate, a spring coiled about said upstanding lug and having, one of its limbs engaging the shank of said secondary scroll-section for biasing the, latter toward said primary scroll-section, and a hollow casing secured in position to house said shank and spring .by a fastening screw threaded into said upstanding lug.

, 11. A hemming attachment for sewing machines comprising, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section twisted with said primary scrollsection to provide a fabric-receiving passageway, means for supporting said secondary scroll-section for adjustment about an axis parallel to the line of the normal feed of the: fabric through the hemmer, and means for locking said secondary scroll-section in adjusted position.

12. A hemming attachment for sewing machines comprising, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section twisted with said primary scrollsection to provide a fabric-receiving passageway, a shank integral with and arranged longitudinally of said secondary scroll-section, a casing mounted upon said base-plate and apertured to adjustably receive said shank, and a set-screw engaging said shank for locking the secondary scroll-section in adjusted position.

13. A hemming attachment for sewing machines comprising, a base-plate, a longitudinally spiraled primary scroll-section secured to said base-plate, a longitudinally spiraled secondary scroll-section twisted with said primary scrollsection to provide a fabric-receiving passageway, a cylindrical horizontal shank integral with and arranged longitudinally of said secondary scrollsection, acasing detachably mounted upon said base-plate and apertured to adjustably receive said shank, and a set-screw threaded into said casing and engaging said shank for locking the secondary scroll-section in adjusted position, said set-screw being accessible through said base-plate.

14. A hemming attachment for sewing machines comprising, a base-plate, a pair of adja cent longitudinally spiraled scroll-sections defining between them a fabric-receiving passageway having a receiving end and a delivery end, a shank formed on one of said scroll-sections adjacent the receiving end of said fabric-receiving passageway, and a casing secured upon said base-plate in advance of the scroll-sections and encompassing said shank, said casing providing a fabric-supporting platform for facilitating the proper presentation of the fabric to the spiraled scroll-sections.

15. A hemming attachment for sewing machines comprising, in combination, a base-plate, a first longitudinally spiraled scroll-section supported by said base-plate, a second longitudinally spiraled scroll-section positioned to define with said first scro1l-section a fabric-receiving passageway, a support for said second scroll-section, and means for adjustably supporting said second scroll-section on said support for bodily movement of said second scroll-section relative to said first scroll-section to augment the inherent flexing of the scroll-sections to vary the capacity of the fabric-receiving passageway.

JOHN P. ENOS. 

